Tiz true: more function=slower boot time, but I'd suggest it is more fundamental than that...
To illustrate:

Getting up in the morning the 'Amiga way':
Booting up...
Who am I? Where am I? - All good - Eyes open.
To do list...
Get up, brush teeth, have shower.
On way to bathroom...
Bladder to brain: Need a pee! - do pee. Bladder sleeps.
Bum to brain: Heavy load alert! - take dump. Rectum sleeps.
Back to to do list...
Teeth brushed, body showered.

All done!
All my brain has had to cope with is booting up & dealing with my to do list.
I've been briefly interupted by 'other functions' but all has been safely & efficiently negotiated...
...shame I'm about to get arrested for not having dressing on my to do list.

Getting up in the morning the 'Linux way':
Booting up...
Who am I? Where am I?
Set up bladder awareness system.
Audit state of bladder - to pee or not to pee...
Set up lower bowel awareness system.
Audit state of bowel - to poo or not to poo...
- All good - Eyes open.
To do list...
Get up, Audit state of bladder, Audit state of bowel, brush teeth, Audit state of bladder, Audit state of bowel, have shower, Audit state of bladder, Audit state of bowel.
Have got up:
Call bladder awareness system.
Audit state of bladder - to pee or not to pee...
Need pee - have pee
Call lower bowel awareness system.
Audit state of bowel - to poo or not to poo...
Need poo - have poo
Have brushed teeth:
Call bladder awareness system.
Audit state of bladder - to pee or not to pee...
No pee
Call lower bowel awareness system.
Audit state of bowel - to poo or not to poo...
No poo
Had shower:
Call bladder awareness system.
Audit state of bladder - to pee or not to pee...
No pee
Call lower bowel awareness system.
Audit state of bowel - to poo or not to poo...
No poo

Phew! All done too.
But damn! That was so much more effort! Not only did I need a much bigger brain to keep track of everything I needed to do, I also needed to think much faster to be able to juggle the 'demands' in real time without slowing or having any accidents...
...and I still didn't get round to putting any clothes on!